Purpose : To assess the effects of cycling cadence, exercise intensity, and preload on blood lactate concentration (BLC), carbohydrate oxidation (CHO), and gross efficiency (GE) during 60-minute cycling sessions. Methods : Eleven male triathletes (age: 28.2 9.2 y, height: 179.9 6.0 cm, body mass: 73.1 4.8 kg, performance level 3) completed 2 incremental load tests to determine peak power (P peak ) and 4 prolonged cycling tests including 20-minute warm-up at 40% P peak followed by a 20-minute load phase at 60% and 70% P peak with a subsequent cooldown at 40% P peak , all at 60 and 100 rpm, respectively. BLC, oxygen uptake, and carbon dioxide production were measured, and GE, CHO, and the fraction of oxygen uptake utilized for CHO (relCHO) were calculated. Results : The higher cadence lowered GE and increased BLC, oxygen uptake, and CHO ( P < .05). RelCHO increased with exercise intensity ( P < .05), but no cadence-related increase was confirmed. CHO and relCHO were lower ( P < .05) at cooldown than at warm-up without changes in BLC. Conclusions : The lack of evidence for a cadence effect on relCHO supports the suggestion that a higher cadence enables a lower CHO at given metabolic demand and given BLC, particularly at lower exercise intensity. A preload-induced decrease in CHO and relCHO may appear at unchanged availability of pyruvate and lactate as indicated by the BLC. In elite cyclists, where GE remains stable or even improves at higher cadences, the ability to sustain CHO stores by higher cadences could provide a significant performance advantage.
Beneke et al. (Wed,) studied this question.